<?php
/**
 * COciSchema class file.
 *
 * @author Ricardo Grana <rickgrana@yahoo.com.br>
 * @link http://www.yiiframework.com/
 * @copyright 2008-2013 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * COciSchema is the class for retrieving metadata information from an Oracle database.
 *
 * @property string $defaultSchema Default schema.
 *
 * @author Ricardo Grana <rickgrana@yahoo.com.br>
 * @package system.db.schema.oci
 */
class COciSchema extends CDbSchema
{
    private $_defaultSchema = '';

    /**
     * @var array the abstract column types mapped to physical column types.
     * @since 1.1.6
     */
    public $columnTypes = array(
        'pk' => 'NUMBER(10) NOT NULL PRIMARY KEY',
        'string' => 'VARCHAR2(255)',
        'text' => 'CLOB',
        'integer' => 'NUMBER(10)',
        'float' => 'NUMBER',
        'decimal' => 'NUMBER',
        'datetime' => 'TIMESTAMP',
        'timestamp' => 'TIMESTAMP',
        'time' => 'TIMESTAMP',
        'date' => 'DATE',
        'binary' => 'BLOB',
        'boolean' => 'NUMBER(1)',
        'money' => 'NUMBER(19,4)',
    );

    /**
     * Quotes a table name for use in a query.
     * A simple table name does not schema prefix.
     * @param string $name table name
     * @return string the properly quoted table name
     * @since 1.1.6
     */
    public function quoteSimpleTableName($name)
    {
        return '"' . $name . '"';
    }

    /**
     * Quotes a column name for use in a query.
     * A simple column name does not contain prefix.
     * @param string $name column name
     * @return string the properly quoted column name
     * @since 1.1.6
     */
    public function quoteSimpleColumnName($name)
    {
        return '"' . $name . '"';
    }

    /**
     * Creates a command builder for the database.
     * This method may be overridden by child classes to create a DBMS-specific command builder.
     * @return CDbCommandBuilder command builder instance
     */
    protected function createCommandBuilder()
    {
        return new COciCommandBuilder($this);
    }

    /**
     * @param string $schema default schema.
     */
    public function setDefaultSchema($schema)
    {
        $this->_defaultSchema = $schema;
    }

    /**
     * @return string default schema.
     */
    public function getDefaultSchema()
    {
        if (!strlen($this->_defaultSchema)) {
            $this->setDefaultSchema(strtoupper($this->getDbConnection()->username));
        }

        return $this->_defaultSchema;
    }

    /**
     * @param string $table table name with optional schema name prefix, uses default schema name prefix is not provided.
     * @return array tuple as ($schemaName,$tableName)
     */
    protected function getSchemaTableName($table)
    {
        $table = strtoupper($table);
        if (count($parts = explode('.', str_replace('"', '', $table))) > 1)
            return array($parts[0], $parts[1]);
        else
            return array($this->getDefaultSchema(), $parts[0]);
    }

    /**
     * Loads the metadata for the specified table.
     * @param string $name table name
     * @return CDbTableSchema driver dependent table metadata.
     */
    protected function loadTable($name)
    {
        $table = new COciTableSchema;
        $this->resolveTableNames($table, $name);

        if (!$this->findColumns($table))
            return null;
        $this->findConstraints($table);

        return $table;
    }

    /**
     * Generates various kinds of table names.
     * @param COciTableSchema $table the table instance
     * @param string $name the unquoted table name
     */
    protected function resolveTableNames($table, $name)
    {
        $parts = explode('.', str_replace('"', '', $name));
        if (isset($parts[1])) {
            $schemaName = $parts[0];
            $tableName = $parts[1];
        } else {
            $schemaName = $this->getDefaultSchema();
            $tableName = $parts[0];
        }

        $table->name = $tableName;
        $table->schemaName = $schemaName;
        if ($schemaName === $this->getDefaultSchema())
            $table->rawName = $this->quoteTableName($tableName);
        else
            $table->rawName = $this->quoteTableName($schemaName) . '.' . $this->quoteTableName($tableName);
    }

    /**
     * Collects the table column metadata.
     * @param COciTableSchema $table the table metadata
     * @return boolean whether the table exists in the database
     */
    protected function findColumns($table)
    {
        $schemaName = $table->schemaName;
        $tableName = $table->name;

        $sql = <<<EOD
SELECT a.column_name, a.data_type ||
    case
        when data_precision is not null
            then '(' || a.data_precision ||
                    case when a.data_scale > 0 then ',' || a.data_scale else '' end
                || ')'
        when data_type = 'DATE' then ''
        when data_type = 'NUMBER' then ''
        else '(' || to_char(a.data_length) || ')'
    end as data_type,
    a.nullable, a.data_default,
    (   SELECT D.constraint_type
        FROM ALL_CONS_COLUMNS C
        inner join ALL_constraints D on D.OWNER = C.OWNER and D.constraint_name = C.constraint_name
        WHERE C.OWNER = B.OWNER
           and C.table_name = B.object_name
           and C.column_name = A.column_name
           and D.constraint_type = 'P') as Key,
    com.comments as column_comment
FROM ALL_TAB_COLUMNS A
inner join ALL_OBJECTS B ON b.owner = a.owner and ltrim(B.OBJECT_NAME) = ltrim(A.TABLE_NAME)
LEFT JOIN user_col_comments com ON (A.table_name = com.table_name AND A.column_name = com.column_name)
WHERE
    a.owner = '{$schemaName}'
	and (b.object_type = 'TABLE' or b.object_type = 'VIEW')
	and b.object_name = '{$tableName}'
ORDER by a.column_id
EOD;

        $command = $this->getDbConnection()->createCommand($sql);

        if (($columns = $command->queryAll()) === array()) {
            return false;
        }

        foreach ($columns as $column) {
            $c = $this->createColumn($column);

            $table->columns[$c->name] = $c;
            if ($c->isPrimaryKey) {
                if ($table->primaryKey === null)
                    $table->primaryKey = $c->name;
                elseif (is_string($table->primaryKey))
                    $table->primaryKey = array($table->primaryKey, $c->name);
                else
                    $table->primaryKey[] = $c->name;
                $table->sequenceName = '';
                $c->autoIncrement = true;
            }
        }
        return true;
    }

    /**
     * Creates a table column.
     * @param array $column column metadata
     * @return CDbColumnSchema normalized column metadata
     */
    protected function createColumn($column)
    {
        $c = new COciColumnSchema;
        $c->name = $column['COLUMN_NAME'];
        $c->rawName = $this->quoteColumnName($c->name);
        $c->allowNull = $column['NULLABLE'] === 'Y';
        $c->isPrimaryKey = strpos($column['KEY'], 'P') !== false;
        $c->isForeignKey = false;
        $c->init($column['DATA_TYPE'], $column['DATA_DEFAULT']);
        $c->comment = $column['COLUMN_COMMENT'] === null ? '' : $column['COLUMN_COMMENT'];

        return $c;
    }

    /**
     * Collects the primary and foreign key column details for the given table.
     * @param COciTableSchema $table the table metadata
     */
    protected function findConstraints($table)
    {
        $sql = <<<EOD
		SELECT D.constraint_type as CONSTRAINT_TYPE, C.COLUMN_NAME, C.position, D.r_constraint_name,
                E.table_name as table_ref, f.column_name as column_ref,
            	C.table_name
        FROM ALL_CONS_COLUMNS C
        inner join ALL_constraints D on D.OWNER = C.OWNER and D.constraint_name = C.constraint_name
        left join ALL_constraints E on E.OWNER = D.r_OWNER and E.constraint_name = D.r_constraint_name
        left join ALL_cons_columns F on F.OWNER = E.OWNER and F.constraint_name = E.constraint_name and F.position = c.position
        WHERE C.OWNER = '{$table->schemaName}'
           and C.table_name = '{$table->name}'
           and D.constraint_type <> 'P'
        order by d.constraint_name, c.position
EOD;
        $command = $this->getDbConnection()->createCommand($sql);
        foreach ($command->queryAll() as $row) {
            if ($row['CONSTRAINT_TYPE'] === 'R') // foreign key
            {
                $name = $row["COLUMN_NAME"];
                $table->foreignKeys[$name] = array($row["TABLE_REF"], $row["COLUMN_REF"]);
                if (isset($table->columns[$name]))
                    $table->columns[$name]->isForeignKey = true;
            }

        }
    }

    /**
     * Returns all table names in the database.
     * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
     * If not empty, the returned table names will be prefixed with the schema name.
     * @return array all table names in the database.
     */
    protected function findTableNames($schema = '')
    {
        if ($schema === '') {
            $sql = <<<EOD
SELECT table_name, '{$schema}' as table_schema FROM user_tables
EOD;
            $command = $this->getDbConnection()->createCommand($sql);
        } else {
            $sql = <<<EOD
SELECT object_name as table_name, owner as table_schema FROM all_objects
WHERE object_type = 'TABLE' AND owner=:schema
EOD;
            $command = $this->getDbConnection()->createCommand($sql);
            $command->bindParam(':schema', $schema);
        }

        $rows = $command->queryAll();
        $names = array();
        foreach ($rows as $row) {
            if ($schema === $this->getDefaultSchema() || $schema === '')
                $names[] = $row['TABLE_NAME'];
            else
                $names[] = $row['TABLE_SCHEMA'] . '.' . $row['TABLE_NAME'];
        }
        return $names;
    }

    /**
     * Builds a SQL statement for renaming a DB table.
     * @param string $table the table to be renamed. The name will be properly quoted by the method.
     * @param string $newName the new table name. The name will be properly quoted by the method.
     * @return string the SQL statement for renaming a DB table.
     * @since 1.1.6
     */
    public function renameTable($table, $newName)
    {
        return 'ALTER TABLE ' . $this->quoteTableName($table) . ' RENAME TO ' . $this->quoteTableName($newName);
    }

    /**
     * Builds a SQL statement for changing the definition of a column.
     * @param string $table the table whose column is to be changed. The table name will be properly quoted by the method.
     * @param string $column the name of the column to be changed. The name will be properly quoted by the method.
     * @param string $type the new column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
     * into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
     * For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
     * @return string the SQL statement for changing the definition of a column.
     * @since 1.1.6
     */
    public function alterColumn($table, $column, $type)
    {
        $type = $this->getColumnType($type);
        $sql = 'ALTER TABLE ' . $this->quoteTableName($table) . ' MODIFY '
            . $this->quoteColumnName($column) . ' '
            . $this->getColumnType($type);
        return $sql;
    }

    /**
     * Builds a SQL statement for dropping an index.
     * @param string $name the name of the index to be dropped. The name will be properly quoted by the method.
     * @param string $table the table whose index is to be dropped. The name will be properly quoted by the method.
     * @return string the SQL statement for dropping an index.
     * @since 1.1.6
     */
    public function dropIndex($name, $table)
    {
        return 'DROP INDEX ' . $this->quoteTableName($name);
    }

    /**
     * Resets the sequence value of a table's primary key.
     * The sequence will be reset such that the primary key of the next new row inserted
     * will have the specified value or max value of a primary key plus one (i.e. sequence trimming).
     *
     * Note, behavior of this method has changed since 1.1.14 release. Please refer to the following
     * issue for more details: {@link https://github.com/yiisoft/yii/issues/2241}
     *
     * @param CDbTableSchema $table the table schema whose primary key sequence will be reset
     * @param integer|null $value the value for the primary key of the next new row inserted.
     * If this is not set, the next new row's primary key will have the max value of a primary
     * key plus one (i.e. sequence trimming).
     * @since 1.1.13
     */
    public function resetSequence($table, $value = null)
    {
        if ($table->sequenceName === null)
            return;

        if ($value !== null)
            $value = (int)$value;
        else {
            $value = (int)$this->getDbConnection()
                ->createCommand("SELECT MAX(\"{$table->primaryKey}\") FROM {$table->rawName}")
                ->queryScalar();
            $value++;
        }
        $this->getDbConnection()
            ->createCommand("DROP SEQUENCE \"{$table->name}_SEQ\"")
            ->execute();
        $this->getDbConnection()
            ->createCommand("CREATE SEQUENCE \"{$table->name}_SEQ\" START WITH {$value} INCREMENT BY 1 NOMAXVALUE NOCACHE")
            ->execute();
    }

    /**
     * Enables or disables integrity check.
     * @param boolean $check whether to turn on or off the integrity check.
     * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
     * @since 1.1.14
     */
    public function checkIntegrity($check = true, $schema = '')
    {
        if ($schema === '')
            $schema = $this->getDefaultSchema();
        $mode = $check ? 'ENABLE' : 'DISABLE';
        foreach ($this->getTableNames($schema) as $table) {
            $constraints = $this->getDbConnection()
                ->createCommand("SELECT CONSTRAINT_NAME FROM USER_CONSTRAINTS WHERE TABLE_NAME=:t AND OWNER=:o")
                ->queryColumn(array(':t' => $table, ':o' => $schema));
            foreach ($constraints as $constraint)
                $this->getDbConnection()
                    ->createCommand("ALTER TABLE \"{$schema}\".\"{$table}\" {$mode} CONSTRAINT \"{$constraint}\"")
                    ->execute();
        }
    }
}
